Use Triamterene as directed by your doctor. Take Triamterene by mouth with food. If you have trouble swallowing the tablet whole, it may be crushed or chewed with a little water. Ask your health care provider any questions you may have about how to use Triamterene.

Drug Class and Mechanism

Triamterene is a potassium-conserving (antikaliuretic) diuretic with relatively weak natriuretic properties. It exerts its diuretic effect on the distal renal tubule to inhibit the reabsorption of sodium in exchange for potassium and hydrogen. With this action, triamterene increases sodium excretion and reduces the excessive loss of potassium and hydrogen associated with hydrochlorothiazide. Triamterene is not a competitive antagonist of the mineralocorticoids and its potassium-conserving effect is observed in patients with Addison's disease, i.e., without aldosterone. Triamterene's onset and duration of activity is similar to hydrochlorothiazide.

Hydrochlorothiazide is a diuretic and antihypertensive agent. It blocks the renal tubular absorption of sodium and chloride ions. This natriuresis and diuresis is accompanied by a secondary loss of potassium and bicarbonate. Onset of hydrochlorothiazide's diuretic effect occurs within two hours and the peak action takes place in four hours. Diuretic activity persists for approximately six to twelve hours.

Missed Dose

If you miss a dose of Triamterene and are taking it regularly, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Storage

Store Triamterene at room temperature, between 68 and 77 degrees F (20 and 25 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep in a tight, light-resistant container. Keep Triamterene out of the reach of children and away from pets.

Warnings/Precautions

Do not use Triamterene if: you are allergic to any ingredient in Triamterene; you are taking potassium supplements, another potassium-sparing diuretic (e.g., amiloride), or an aldosterone blocker (e.g., eplerenone); you are unable to urinate or have high blood potassium levels or severely decreased liver or kidney function. Contact your doctor or health care provider right away if any of these apply to you.

Important:

Triamterene may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use Triamterene with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it. Check with your doctor before you use a salt substitute or a product that has potassium in it. Tell your doctor or dentist that you take Triamterene before you receive any medical or dental care, emergency care, or surgery. Lab tests, including blood electrolytes, blood cell counts, kidney and liver function tests, blood uric acid levels, and blood pressure, may be performed while you use Triamterene. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments. Use Triamterene with caution in the elderly; they may be more sensitive to its effects. Triamterene should not be used in children; safety and effectiveness in children have not been confirmed. Pregnancy and breast-feeding: It is not known if Triamterene can cause harm to the fetus. If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Triamterene while you are pregnant. It is not known if Triamterene is found in breast milk. Do not breast-feed while taking this medicine.

Possible Side Effects

Check with your doctor if any of these most common side effects persist or become bothersome: diarrhea; headache; loss of appetite; nausea; weakness. Seek medical attention right away if any of these severe side effects occur: severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); dry mouth; excessive thirst; slow or irregular heart rate; unusual muscle weakness; unusual tiredness; vomiting; yellowing of the skin or eyes.

More Information

Triamterene is to be used only by the patient for whom it is prescribed. Do not share it with other people.

If your symptoms do not improve or if they become worse, check with your doctor.